A. Field of Invention
The present invention relates generally to trailers and methods for loading watercraft vehicles. In particular, the present invention pertains to a trailer guide to assist in retrieving a pontoon boat from a body of water.
B. Problems in the Art
Trailers offer a number of advantages over transporting a boat directly upon an automobile, sport utility vehicle, pick-up truck, or flat-bed truck. Among these advantages are: (1) loading and unloading the boat at an elevation closer to the ground, (2) the ability to unload the boat directly into a waterway and reload the boat while still maintaining vehicle drive wheels upon dry ground for good traction, (3) ready storage with quick and simple retrieval by simply unhitching the trailer, and (4) the ability to load and transport boats much longer than the motor vehicle. Since in some instances the boats are loaded or unloaded on a daily basis, these trailers can greatly simplify the loading and unloading process.
Numerous attempts have been made to solve the problems of trailering watercraft and more particularly pontoon boats. Pontoon boats have presented some challenges to trailer design that are relatively unique and elusive to solve. It is well known in the prior art that retrieving a pontoon boat from the water is very difficult. One issue is the amount of assistance needed from persons other than the driver of the boat. Another issue is the amount of pontoon boat drift that can be caused by wind or current acting upon a boat already in the water. Various trailers and trailer guides have been utilized to address one or both of these issues.
In some cases, prior art trailers are designed to accommodate several different types of boats with distinct hull designs. However, most trailers are designed for only one or a limited few types of boat hulls. For example, a trailer designed to carry a typical fishing boat will be shaped to accommodate the relatively deep keel and steeply sloping sides of the boat. In contrast, a shallow water boat is designed with a relatively flat bottom. Consequently, a carrier designed to receive the keel and steep sides of a fishing boat will not receive and support a flat-bottom boat. The same holds true for other types of boats, such as catamarans and pontoon boats, which generally have unique multiple hull designs. These and other types of boats have consequently required specific trailer designs or accommodations.
In the specific case of a pontoon boat, the boat will generally include two or more hulls, commonly called pontoons, which are elongated tubes that may typically be sealed and hold air or another gas therein. Generally, across the top of the pontoons there will be attached a deck which supports passengers, a boat engine, and other various components, while simultaneously fixing the position of the pontoons relative to each other. One common technique for assisting a person with the loading and unloading of the boat is the utilization of rollers. For example, a hand or powered winch may be provided to draw the boat onto and across the rollers. Since the rollers are able to roll across the exterior of the boat, such as along the keel or along the port or starboard undersides, there is almost no scraping or sliding of the boat which would otherwise damage the boat. Additionally, there is reduced force required to move the boat over the rollers. Consequently, a winch and cable may be hand-turned in many instances, and such winch and cable are generally relatively low cost commodity items.
While the rollers tend to simplify the unloading of a boat, they do not provide adequate guidance for retrieving the boat. When trailing the boat, rollers are often beneath the surface of the water and are not visible to the operator of the boat. As a result, sub-surface rollers do not adequately address the difficulty of retrieving a multiple hulled boat, such as a pontoon boat, from a body of water. Conventional rollers have very little surface area in contact with the boat hull and therefore may not guide the boat into a resting position when the trailer is pulled out of the water. Another problem associated with rollers is that they may not provide good support for the boat. Again this is a result of the small surface area of the roller in contact with hull of the boat. At the point of contact, the forces placed upon the boat bull by the total weight of the boat and contents may cause the boat hull to deform. Even absent noticeable deformation, the stresses generated adjacent a roller tend to be very high, leading to premature failure of the boat hull. While additional contact may be obtained with the use of more rollers, which would thereby reduce the stress between the boat and any given roller, rollers tend to be relatively expensive. Consequently, supporting more than a very minor amount of surface area on the boat with rollers can be cost prohibitive.
Typical of this type of roller is that disclosed by Rankin in U.S. Pat. No. 3,455,472 issued on Jul. 15, 1969. Rankin utilizes axially spaced spools to support the keel of the boat. The rollers contact only a small surface area of the keel of the boat. Furthermore, the rollers utilized by Rankin would not be visible to the operator of the boat during conventional retrieval from water. Thus the rollers as disclosed by Rankin would not be ideal for retrieving and loading a pontoon boat. This can be particularly true in the presence of dramatic effects of drift caused by a current or side wind.
Another common technique for retrieving and supporting a pontoon boat upon a trailer is the use of V-shaped bunks, which are angled solid surfaces against which a boat hull(s) is rested; typically along a substantial amount of the longitudinal length of the hull(s). In the case of a V-shaped bunk trailer for a dual-pontoon pontoon boat, the pontoons are solidly supported across and along substantially the entire bunk, rather than across a few square inches of roller. Since such bunks are low-cost, typically comprising little more than a beam having a non-marring surface, the cost of supporting a large surface area is quite small and economical. It also leads to better transport, including a substantial reduction in the stress forces generated within the boat hull and a resultant reduction in the likelihood for damage to the boat during transport. Unfortunately, however, this type of trailer provides very little assistance in guiding a multiple-hulled vessel, such as pontoon boat, to a final resting position. To illustrate, when retrieving the boat the margin of error to “fit” each pontoon into its respective V-shaped bunk is very small; often around 4 inches. The operator also does not have convenient visual signposts to determine proper alignment as the trailer and V-shaped bunks are mostly submerged and not readily visible. Further complicating the retrieval of the pontoon boat can be the presence of a side wind, transverse currents, or other side forces. They may cause the boat to drift or move considerably, making it even more difficult to align the boat so that the pontoons fit into their V-shaped bunks.
Typical of a trailer utilizing V-shaped bunks is that disclosed by Wilson in U.S. Pat. No. 4,801,153 issued on Jan. 31, 1989. In this trailer, a pair of glides is provided for supporting each of the pontoons. A winch is provided for pulling the pontoon boat onto the trailer. Rollers are associated with each glide such that as the winch is operated to pull the pontoon boat onto the trailer, the pontoons engage the rollers which are intended to enable easier movement of the pontoon boat. Vertical supports 72 extend from the trailer frame upward at essentially exactly the inside distance between pontoons 62 and 64. Supports 72 can be used to guide the boat onto the trailer. However, it is well known that when loading a boat, the trailer must be at least partially submerged in order to begin the loading process. Otherwise, the boat would have to be lifted from the water prior to loading it on the trailer. After the rear of the trailer has been submerged, the boat is floated over at least a portion of the trailer and then a cable connected at one end to the winch is connected at its distal end to the boat (usually the bow). The winch is then operated to pull the bow of the boat toward the front end of the trailer. When the boat is floated over the trailer, it is well known that the boat must be maintained in alignment over the trailer such that when the trailer is pulled from the water and the boat engages the trailer, the entire boat drops into and is perfectly nested in the trailer. If the boat is not in alignment with the trailer, damage may be sustained by one or both. The boat-loading process must be reversed and started over. It can take several tries. Sometimes, especially with significant cross winds or currents, loading can be unmanageable. It is well known that boats tend to drift when in the water, making the task of loading the boat difficult. Although Wilson U.S. Pat. No. 4,801,153 discloses a trailer adapted for loading and carrying a pontoon boat, he does not account for drift. Typically, there will be at least one person in the water around the boat to assist in aligning the boat over the trailer. This is in addition to the person who attaches the winch line to the boat and operates the winch to pull the boat over the trailer. Because of the problems caused by boat drift, it is known that it is difficult, and in many instances impossible, to load a pontoon boat by one's self, or without having to have at least one person in the water to align the boat with the trailer.
A technique used to remedy the affects of drift and provide assistance to the operator while retrieving the boat is to use upwardly extending guide posts. Typical of this arrangement is that disclosed by Marshburn in U.S. Pat. No. 5,853,185 issued on Dec. 29, 1998. In this trailer, a pair of guide posts may be pulled apart to engage the interior side of each pontoon. The two guide posts are biased against each other by a tension spring. A winch mounted on the trailer pulls the guide posts apart until engagement with the interior side of the each pontoon. One problem associated with trailers utilizing a straight inside guide as disclosed by Marshburn is retrieving a pontoon boat fitted with strakes. A strake, as is understood in the art, is an angled metal appendage that is welded to the interior lower quarter of each pontoon tube. Strakes can run for along the lower quarter of the pontoon for the entire length of the boat or less depending on the use of the boat. Boat owners often use strakes to help the boat plane and increase the top end speed of the boat to facilitate activities such as water skiing or getting air beneath a wakeboard. A strake increases available flat lifting surface to help generate more lift. However, a problem occurs when an operator retrieves a pontoon boat from a body of water using a trailer guide with straight inside guides. As the trailer is pulled out of the water, the strake tends to land on top of the guide and is thereby prevented from settling into the V-shaped bunk. Accordingly, a problem is presented when attempting to reduce the affects of drift while still allowing for the retrieval and loading of pontoon boats fitted with strakes. Strakes or other outwardly extending features on pontoons can make it more difficult to accurately trailer the pontoon boat, even in calm water.
Other trailers have been disclosed having guides to launch and load boats from and onto trailers. Examples are disclosed by Park in U.S. Pat. No. 4,099,279 and Palamara in U.S. Pat. No. 4,103,925. Each disclose side rails for guiding a boat onto a trailer. These trailers are used for carrying a single hull boat such as a ski boat or fishing boat. The side rails, as illustrated, may be helpful in nesting a pontoon boat onto a trailer, but interfere with loading the boat onto the trailer when the boat becomes misaligned with the trailer due to, for instance, side wind.
Beelow, U.S. Pat. No. 4,114,772, discloses a trailer which may be raised and lowered in order to assist in the launching and loading of a pontoon boat. In order to load a pontoon using the Beelow trailer, the pontoon must be stabilized, generally on land. The trailer is then backed under the pontoon. When the trailer is positioned under the boat, the trailer is lifted into engagement with the boat. This device does not disclose a means for aligning the boat with the trailer to assist in the loading process. Notably, and most importantly, Beelow does not disclose a method for overcoming the effects of drift on a pontoon boat in the water while approaching the trailer.